* FIX [exchange_client] Resolve TSAN data race

Signed-off-by: Moi Ran <maoyi.ran@emqx.io>
nanomq · Nov 25, 2023 · 583bf19 · 583bf19
1 parent 8334db5
commit 583bf19
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Showing 2 changed files with 43 additions and 12 deletions.
diff --git a/include/nng/exchange/exchange_client.h b/include/nng/exchange/exchange_client.h
@@ -13,6 +13,7 @@ typedef struct exchange_node_s exchange_node_t;
 
 struct exchange_node_s {
 	exchange_t      *ex;
+	exchange_sock_t *sock;
 	nni_aio         saio;
 	nni_lmq         send_messages;
 	nni_list_node   exnode;
@@ -22,6 +23,7 @@ struct exchange_node_s {
 
 struct exchange_sock_s {
 	nni_mtx         mtx;
+	nni_atomic_bool closed;
 	nni_list        ex_queue;
 };
 

diff --git a/src/mqtt/protocol/exchange/exchange_client.c b/src/mqtt/protocol/exchange/exchange_client.c
@@ -33,8 +33,9 @@ exchange_add_ex(exchange_sock_t *s, exchange_t *ex)
 
 	node->isBusy = false;
 	node->ex = ex;
+	node->sock = s;
 
-	nni_aio_init(&node->saio, exchange_send_cb, ex);
+	nni_aio_init(&node->saio, exchange_send_cb, node);
 	nni_lmq_init(&node->send_messages, 1024);
 
 	NNI_LIST_NODE_INIT(&node->exnode);
@@ -53,6 +54,8 @@ exchange_sock_init(void *arg, nni_sock *sock)
 	NNI_ARG_UNUSED(sock);
 	exchange_sock_t *s = arg;
 
+	nni_atomic_init_bool(&s->closed);
+	nni_atomic_set_bool(&s->closed, false);
 	nni_mtx_init(&s->mtx);
 	NNI_LIST_INIT(&s->ex_queue, exchange_node_t, exnode);
 
@@ -63,6 +66,25 @@ static void
 exchange_sock_fini(void *arg)
 {
 	exchange_sock_t *s = arg;
+	exchange_node_t *ex_node;
+
+	NNI_LIST_FOREACH (&s->ex_queue, ex_node) {
+		nni_aio_fini(&ex_node->saio);
+		nni_lmq_fini(&ex_node->send_messages);
+		nni_mtx_fini(&ex_node->mtx);
+		exchange_release(ex_node->ex);
+	}
+
+	ex_node = NULL;
+	while (!nni_list_empty(&s->ex_queue)) {
+		ex_node = nni_list_last(&s->ex_queue);
+		if (ex_node) {
+			nni_list_remove(&s->ex_queue, ex_node);
+			nng_free(ex_node, sizeof(*ex_node));
+			ex_node = NULL;
+		}
+	}
+
 	nni_mtx_fini(&s->mtx);
 	return;
 }
@@ -80,18 +102,9 @@ exchange_sock_close(void *arg)
 	exchange_sock_t *s = arg;
 	exchange_node_t *ex_node;
 
+	nni_atomic_set_bool(&s->closed, true);
 	NNI_LIST_FOREACH (&s->ex_queue, ex_node) {
-		exchange_release(ex_node->ex);
-		nni_lmq_fini(&ex_node->send_messages);
-	}
-
-	ex_node = NULL;
-	while (!nni_list_empty(&s->ex_queue)) {
-		ex_node = nni_list_last(&s->ex_queue);
-		if (ex_node) {
-			nni_list_remove(&s->ex_queue, ex_node);
-			nng_free(ex_node, sizeof(*ex_node));
-		}
+		nni_aio_close(&ex_node->saio);
 	}
 
 	return;
@@ -157,7 +170,23 @@ exchange_send_cb(void *arg)
 	exchange_node_t *ex_node = arg;
 	nni_msg *    msg = NULL;
 
+	if (ex_node == NULL) {
+		return;
+	}
+
+	exchange_sock_t *s = ex_node->sock;
+	if (nni_atomic_get_bool(&s->closed)) {
+		// This occurs if the mqtt_pipe_close has been called.
+		// In that case we don't want any more processing.
+		return;
+	}
+
 	nni_mtx_lock(&ex_node->mtx);
+	if (nni_aio_result(&ex_node->saio) != 0) {
+		nni_mtx_unlock(&ex_node->mtx);
+		return;
+	}
+
 	if (nni_lmq_get(&ex_node->send_messages, &msg) == 0) {
 		nni_mtx_unlock(&ex_node->mtx);
 		(void)exchange_handle_msg(ex_node->ex, msg);